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Acorn Woodpecker Resident East of the Sierra Nevada in California

Sturgis Mckeever, Lowell Adams
Publication Information
Journal: 
Condor
Volume: 
62
Issue: 
4 (July-August)
Section: 
From Field and Study
Year: 
1960
Pages: 
297

Acorn Woodpecker Resident East of the Sierra Nevada in California.-The Acorn Woodpecker (Bolanosphyra formicivora) has been considered a resident in California only in that part of the state lying west of the Sierra Nevada where oak trees are present. There is only one record of occurrence on the east side of the Sierra in California; a single specimen was taken near Lone Pine, Inyo County, on September 8 (Grinnell and Miller, Pac. Coast Avif. No. 27, 1944:232). In their work on the vertebrates of the Lassen Peak area, Grinnell, Dixon, and Linsdale (Univ. Calif. Publ. Zool., 35:250) found no Acorn Woodpeckers east of the western edge of the yellow pine belt.

On June 4, 1959, we observed an Acorn Woodpecker near a stand of black oaks (Quercus kelloggii) about 5 miles southeast of Janesville, Lassen County, California, along highway 395. On June 21, another individual was found in the same locality, and four others were observed in the town of Janesville. Further observations on June 28 revealed the presence of a nest containing young in a black oak one-half mile southwest of Janesville. In this area we found three dead ponderosa pines (Pinw ponderosa) covered with typical nut-storage holes, many of which were filled with acorns. The ground beneath one of the trees was covered with acorn shells to a depth of over two inches. Black oaks were abundant in this area.

Specimens were collected at Janesville for subspecific identification. A male and female were taken on July 4, 1959, and four females were collected on October 2. Comparison of these specimens with others at the Museum of Vertebrate Zoology show that they belong to Belanosphyra formicivora bairdi. All were typical of this subspecies except the two specimens collected in July ; these had orangered napes instead of the bright red of all other specimens examined.

Black oaks occur in a continuous stand along the base of the Sierra from seven miles south of Janesville north to Susanville. From Susanville the stand extends west for a short distance along the lower portion of the Susan River and east along Antelope Mountain to Willow Creek. No other oaks occur within several miles of this stand. The Acorn Woodpecker population in the Janesville-Susanville area apparently is therefore an isolated one.-STuxcIs MCKEEVER, Department of Zoology, University of California, Davis, and LOWELL ADAMS, Southwest Forest and Range Experiment Station, United States Forest Service, Berkeley, California, December 4, 1959. 

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